With high revving SR20DET engines you run the risk of the rocker arms bouncing off the lifters and even snapping at very high RPMs.
This is especially of concern if you have upped your rev limit, if you're running aftermarket cams or if you spend a lot of time on the limiter.
These stainless steel rocker arm stoppers bolt on just above the cams and rocker arms to ensure that this doesn't occur.
Note: On the UK spec SR20DET engine, you will need to cut a small portion of the webbing off the inside of the cam cover to fit these. Just ask if you would like details on this.
Note - the use of rocker arm stoppers comes highly recommended by Bee-R when using their rev limiters as these cause extra stress on the rocker arms